1969 427 4 bolt main or 2 bolt main

[vetteboy86]

My boss was wondering if his 427 was a 2 or 4 bolt main engine. My initial feeling is that it is a 4 bolt because I thought they went from 4 to 2 sometime in the mid 70's. I cannot be sure though. The motor has the 4 barrel carb instead of the 3x2 so is that the 390 hp version.

 

[JohnZ]

If the holes above the oil filter are large and tapped as in the photo below, it's a 4-bolt block; if they aren't, it's a 2-bolt block.

 

[vetteboy86]

I will have him check this.

Thanks,
Craig